Mars

First Mars was the setting of imaginary declining civilizations; then it was a dead, cratered, Moon-like world. Thanks to a coordinated Mars exploration program that began in 1996 and continues to the present day, we now know Mars better than any world other than our own, yet we have more questions than ever.

Geologically, Mars is quiescent, but its atmosphere breathes and changes from year to year, interacting in complex ways with the water sequestered in Mars' ice caps and permafrost. Water does not, today, flow on Mars, but it evidently has in the past, and it may flow again in the future when Mars' rotation axis tilts much more steeply. Did Mars ever look like Earth, or has it always been as cold and dry as an Antarctic desert? Has there ever been the right combination of liquid water, available energy, and time to permit life to begin on Mars?

Latest Blogs from Mars

After three weeks of being in a communications blackout on the other side of the Sun during the Earth-Mars solar conjunction, Opportunity phoned home, reporting that she is healthy and ready to continue her mission.

Opportunity spent a mostly merry month of May on Mars touring Spirit of St. Louis Crater, stopping at science targets named in honor of Charles Lindbergh and the incredible flight he took 88 years ago.

More Mars

Mars' axial tilt is similar to Earth's, and its days (or sols) are similar in length, so it has similar seasons. But its elliptical orbit makes seasons more extreme in the southern hemisphere. This page lists dates for seasonal changes and turnover of Mars Years.